1. Reading increases your vocabulary.

A University of London longitudinal study tested vocabulary skills of the same people at ages 16 and 42 and found at the younger age the average test score was 55 percent. Later in life scores averaged 63 percent on the same test, indicating that humans continue to learn language skills even as adults. And the study participants who frequently read for pleasure made the highest gains on the test.

Researchers at the New School for Social Research in New York have determined that reading literary fiction--books that have literary merit and don't fit into a genre--enhances what scientists call "Theory of Mind (ToM), or an ability to understand the mental states of others. This skill "enables the complex social relationships that characterize human societies," the authors write.

3. Reading can lower your stress level.

A study conducted at the University of Sussex in England found that only six minutes of reading was enough of a distraction to reduce participants' stress levels by 68 percent. The relaxation effect achieved by reading was stronger than listening to music, drinking a cup of tea or coffee or taking a walk.

4. Reading can make you self-confident.

That's according to Susan Cain, author of Quiet: The Power of Introverts, who said identifying with introverted yet admirable central characters made her feel as if she was in the mainstream as a child. "Books, especially children's books, are one of the few media to portray introverts as intellectually and emotionally aflame, as opposed to aloof, flawed, or dull," she writes. "This is especially important for children, who seem to read only for plot but are actually forming their view of the world -- and of their places in it."

5. Reading changes the circuitry of the brain.

Researchers at Emory University in Atlanta conducted functional magnetic resonance imaging (fMRI) scans of 21 undergraduate students all tasked with reading the novel Pompeii by Robert Harris. Days after reading sections of the book, results showed heightened connectivity in the areas of the brain involved in receptivity for language as well as physical sensation and movement.

6. Reading is a habit practiced by successful people.

It's because high achievers believe in self-improvement. In fact, countless successful executives have shared with me the books they say have helped them get ahead in business and life. Perennial favorites include: Shoe Dog by Phil Knight; Finding my Virginity by Richard Branson; and The Hard Thing About Hard Things by Ben Horowitz.